Ken Asakawa1, Hitoshi Ishikawa2, Shigekazu Uga2, Kimiyo Mashimo3, Kimiya Shimizu3, Mineo Kondo4, Hiroko Terasaki5. 1. Department of Orthoptics and Visual Science, Kitasato University School of Allied Health Sciences, 1-15-1 Kitasato, Minami-Ku, Sagamihara, Kanagawa, 252-0373, Japan. asaken@kitasato-u.ac.jp. 2. Department of Orthoptics and Visual Science, Kitasato University School of Allied Health Sciences, 1-15-1 Kitasato, Minami-Ku, Sagamihara, Kanagawa, 252-0373, Japan. 3. Department of Ophthalmology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan. 4. Department of Ophthalmology, Mie University Graduate School, School of Medicine, Mie, Japan. 5. Department of Ophthalmology, Nagoya University Graduate School, School of Medicine, Nagoya, Japan.
Abstract
PURPOSE: To investigate the process of retinal degeneration by analyzing the functional and morphological findings in transgenic rabbits with a Pro347Leu rhodopsin mutation. METHODS: Wild-type (WT) and transgenic (Tg) rabbits at ages 4, 8 and 12 months were used. We conducted functional evaluation by recording the changes in the pupil response to red and blue light stimulation and the amplitude of the electroretinography (ERG). Morphologically, rod and cone distribution was examined using light and electron microscopy. Immunostaining for the identification of retinal ganglion cells (RGCs) was also confirmed by injecting a TUJ-1 monoclonal antibody. RESULTS: Pupil constriction for infrared pupillography and the a- and b-waves for ERG in Tg rabbits decreased with increasing age; the differences were compared to the age-matched WT rabbits. The subnormal ERG in the Tg rabbits, especially the a-wave decrease and pupil constriction with a long latency time, was induced only during exposure to blue light stimulation at 12 months. Light and electron microscopic findings showed a progressive loss of photoreceptor cells over time manifesting by 8 months in the peripheral retina. Moreover, pyknotic nuclei of the outer nuclear layer in the center of the visual streak were observed. At 12 months, there was disappearance of the rods and ballooning degeneration of the cones. Some remaining RGCs had large cell bodies with long branching dendrites. CONCLUSIONS: The changes in the pupil light response and amplitude of the ERG could be used to predict the state of retinal degeneration in the Tg rabbit.
PURPOSE: To investigate the process of retinal degeneration by analyzing the functional and morphological findings in transgenic rabbits with a Pro347Leurhodopsin mutation. METHODS: Wild-type (WT) and transgenic (Tg) rabbits at ages 4, 8 and 12 months were used. We conducted functional evaluation by recording the changes in the pupil response to red and blue light stimulation and the amplitude of the electroretinography (ERG). Morphologically, rod and cone distribution was examined using light and electron microscopy. Immunostaining for the identification of retinal ganglion cells (RGCs) was also confirmed by injecting a TUJ-1 monoclonal antibody. RESULTS: Pupil constriction for infrared pupillography and the a- and b-waves for ERG in Tg rabbits decreased with increasing age; the differences were compared to the age-matched WT rabbits. The subnormal ERG in the Tg rabbits, especially the a-wave decrease and pupil constriction with a long latency time, was induced only during exposure to blue light stimulation at 12 months. Light and electron microscopic findings showed a progressive loss of photoreceptor cells over time manifesting by 8 months in the peripheral retina. Moreover, pyknotic nuclei of the outer nuclear layer in the center of the visual streak were observed. At 12 months, there was disappearance of the rods and ballooning degeneration of the cones. Some remaining RGCs had large cell bodies with long branching dendrites. CONCLUSIONS: The changes in the pupil light response and amplitude of the ERG could be used to predict the state of retinal degeneration in the Tg rabbit.
Authors: E Tan; Q Wang; A B Quiambao; X Xu; N M Qtaishat; N S Peachey; J Lem; S J Fliesler; D R Pepperberg; M I Naash; M R Al-Ubaidi Journal: Invest Ophthalmol Vis Sci Date: 2001-03 Impact factor: 4.799
Authors: S Machida; M Kondo; J A Jamison; N W Khan; L T Kononen; T Sugawara; R A Bush; P A Sieving Journal: Invest Ophthalmol Vis Sci Date: 2000-09 Impact factor: 4.799